- #1

Natchanon

- 31

- 3

**1. The problem statement**

A small coin of mass m is placed on a turntable a distance a from the axis. Imagine that the surface is a little sticky, so the coin does not slide immediately. The turntable (initially at rest) is rotated at constant angular acceleration α, beginning at t=0.

a.) Find the three fictitious forces as functions of time. (find both magnitudes and directions in polar unit vectors)

b.) If you are given the static friction coefficient μ, find the time elapsed before the coin begins to slide. (Hint: This will depend on the net lateral force on the co in.)

## Homework Equations

ma_rot = f - mω x (ω x r) - 2mω x v -mα x r

## The Attempt at a Solution

I want to know if I understand this correctly. The coin will start to slide when the net force keeping it in circular motion, that is friction + coriolis + centrifugal + Euler, equals zero, correct? Does that mean all I need to do is to find the net force from its x and y components and set it equal to zero?